1. Field of the Invention
The present invention relates to a method and an apparatus for depositing a silicon-containing film.
2. Description of the Related Art
As described in Japanese Patent No. 5599350, a film deposition method performed in a vacuum chamber is known that includes an adsorption step of causing a first reaction gas to adsorb on a substrate, a deposition step of depositing a reaction product on the substrate by causing the first gas to adsorb on the substrate to react with a second reaction gas, a treatment/etching step of modifying and etching the reaction product by supplying an activated modification gas and an activated etching gas to the substrate, and an etching step of etching the reaction product by supplying an etching gas to the substrate, wherein the etching step is performed after repeating the adsorption step, the depositing step and the treatment/etching step in this order.
According to the film deposition method, the etching is performed immediately after the reaction product is deposited on a recessed portion such as a trench formed in a surface of the substrate. Hence, an opening (upper end) of the recessed portion can be prevented from being blocked by the reaction product, and the film deposition for filling the recessed portion with the film can be performed while preventing a void and a seam from being generated in the film.
However, in the method described in Japanese Patent No. 5599350, plasma is used to perform the treatment/etching step and the etching step. When using the plasma, it is difficult to make shapes of the film filled in the recessed portions uniform across the wafer, and the film deposition apparatus is likely to grow in size due to the installation of the plasma unit.